What is proficiency testing (PT)?
In laboratory medicine, proficiency testing (PT) is a way of evaluating how well a medical laboratory performs a particular test in comparison to another laboratory using pre-established criteria. For example, to determine if laboratory A is accurately measuring blood glucose, it requests a pre-measured sample from laboratory B, runs that sample through its systems, and compares the results. If the measurement obtained by laboratory A is the same as the measurement obtained by laboratory B, then laboratory A is performing its test correctly.
This is a simple example and, in today’s world, proficiency testing is a much more sophisticated and formalized operation, with pre-measured samples coming from commercial suppliers that specialize in providing samples and statistical analysis for PT. However, the principle is the same: by comparing results across laboratories, patients, customers and laboratories themselves can be confident in the quality of services offered.
Why does the DAP require PT?
The DAP requires PT to protect patients and the public. PT is critical to evaluating the quality of test results produced by the medical laboratory. Without PT, medical laboratories might perform tests and release results without knowing they might be inaccurate. By requiring labs perform PT, the DAP enhances public safety and gives confidence to healthcare providers using laboratory services in BC.
How does PT fit into the DAP’s assessment process?
The DAP on-site assessments of medical laboratories occur once every four years. In between these on-site assessments, the DAP requires that laboratories perform PT for all applicable tests within their scope of accreditation, usually by working with a professional, third-party proficiency testing supplier. The DAP requires laboratories participate in a minimum of two PT testing events (challenges) per year for each test within their scope of accreditation.
What happens if proficiency testing is unacceptable?
Throughout the accreditation cycle the DAP receives and reviews copies of PT reports for each laboratory. Unacceptable PT results are flagged so the DAP can monitor that laboratories are submitting a PT Investigation and Exception Response Form for DAP reportable exceptions.
The laboratory investigates unacceptable PT results under the guidance of their medical director. If the unacceptable results meet the DAP reportable exceptions criteria the laboratory sends the DAP a PT Investigation and Exception Response Form which summarizes the investigation and corrective actions taken. If the results are not reportable to the DAP, the laboratory retains the investigation records as part of their quality management system records.
In cases where the medical laboratory demonstrates ongoing, unacceptable PT performance, the matter is referred to the DAP Committee for reconsideration of that medical laboratory’s accreditation award.
What is new for 2018 in the PT monitoring program?
The DAP has clarified its expectations for medical laboratories:
- Frequency for proficiency testing – requirements vary by accreditation type:
- Provisionally accredited facilities must complete a minimum of two samples and one test event prior to full DAP on-site assessment
- Fully accredited facilities must complete a minimum of four samples and two testing events per year
- Time frame for submitting PT enrolment and attestation forms to the DAP is set for three weeks after receiving a provisional award, annually thereafter.
- Escalation process – the DAP has more clearly defined its processes and criteria for the escalation of PT exceptions.
Facilities are always encouraged to contact the DAP if they have questions. The DAP Laboratory Medicine Proficiency Testing Manual is available on the College website.